Process and apparatus for storing and shipping liquefied gases



E. A. JOHNSON, JR 2,784,560 PROCESS AND APPARATUS FOR STORING AND SHIPPING LIQUEFIED GASES 2 Sheets-Sheet l Tlc l.

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March 12', 1957 Filed Feb. 11, 1954 March 12, 1957 A. JOHNSON, JR PROCESS AND APPARATUS FOR STORING Filed Feb. 11, 1954 AND SHIPPING LIQUEFIED GASES 2 Sheets-Sheet 2 United States Patent PRO CESS ANDAPPARATUS-FOR STORING AND SHIPPING LIQUEFIED GASES Evan A. Johnson, Jr.,"Scarsdale, N. Y., assignor to American MesserCorporation, New 'York, N. Y., a corporation ofNew York Application February 11, 1954, Serial No. 409,600

2 Claims. (Cl. 62-1) This invention relates to processesand apparatus for storing and shipping liquefied gases, and=particularlyfor avoiding evaporation losses of a valuable gas.

While the storage of liquefied gases can readily be effected at low temperatures, the use of refrigerating means of the usual recirculating types is cumbersome and expensive and, when the gas is one-such-as argon, which liquefies at'low temperatures, or when the gas is to be transported in its liquid state, the drawbacks in employment of the usual means for maintaining the liquefied gas at low temperatures may be almostprohibitive.

Withthe foregoing and other considerations in view, the'present invention contemplates the use, in preventing escape of a'valuable gas, of an expendable gasunder conditions'such that it will boil at alower' temperature than the valuable gas. The expendable gas is allowed to evaporate and escape'as needed to prevent such rise in temperature as would cause expansion ofthe valuable gas tothe point where it would force open a safety valve associated with its container. The valuable gas is thus preserved at the expense of the expendable gas, but without the use of costly or cumbersome procedure or apparatus. The expendable gas may be one which has a lower boiling point than that of the valuable gas, or the relative pressure conditions of the two gases may be so adjusted that the expandable gas will boil before the valuable gas boils.

In various of its more specific aspects, the invention contemplates the filling of the container only partially so as to leave an area for evaporation of the valuable gas, the maintenance of the valuable gas at a temperature of not over minus 100 F., the provision of an elongated restricted channel for the valuable gas, the provision with in the container of a receptacle for the expendable gas, and the provision of various unusual and inventive cornbinations of steps and elements.

Argon is an example of a valuable gas for use with which the invention is well suited; but it is adapted for use in the storage of any of a variety of rare or otherwise valuable gases, and of gases in particularly pure form, as purified nitrogen, for example.

Liquefied commercial nitrogen, air, and other lowerboiling inexpensive liquefied gases are examples of gases which may be permitted to escape under controlled conditions in order to maintain a more valuable higher-boiling gas in liquefied form. Other gases may be used under special conditions. For example, oxygen may be used with argon when the argon is under extra pressure, and, ordinarily, when means to recover the oxygen are provided.

The invention accordingly comprises the several steps and the relation and order of one or more of such steps with respect to each of the others, and the apparatus embodying features of construction, combinations of elements, and arrangement of parts which are adapted to effect such steps, all as exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims,

For a fuller understanding of the nature and objects of 'theinvention, reference should be had to the following 'det-ailed'description taken in connection with the accompanying drawing, in which:

Figure 1 shows somewhat diagrammatically one form of-a process and, in cross section, an apparatus embodyin g the invention; and

Fig.2 'showsa modified form.

'As-exemplified in Fig. 1, there is provided a storage container 5 in-the'form of a metallic cylinder containing a body oflique fie'd valuable gas 6for example, liquid argon-and providing an area 7 thereabove for containing evaporated gaseous argon. Within the area 7, in the present instance,'is a receptacle 10 containing a liquefied expendable gas -I2,preferably one having a lower boiling point than the argon-liquefied commercial nitrogen, for example. The receptacle 10 is itself in the form of a metallic cylinder so asto be in heat-transfer relationship withthe argon within the container 5 and is equipped with an'outlet 14,normally closed, with a back pressure regulator comprising a valvelS and an adjustable pressure'control '16. The containerS is equipped with a safety valve 18 to which a conduit 20 leads. The control member'1'6 will beso set as to permit the escape of nitrocated by the diagrammatic showing.

The container 5 is insulated against access of heat thereto, as by an insulating layer, such as shown at 25, by a suitable refrigerating layer, or by other suitable arrangement.

The container 5 is filled-ordinarily only partially filledW.ith the argon or other valuable gas, and the safety valve set to open before undue strain is put on the container by the expansion of the gas. The-receptacle 10 is filled with a suitable liquefied expendable gas-for instance, nitrogen-and the valuable gas is ready for storage or shipment. Whenever the temperature in proximity to the receptacle 10 reaches a point where the boiling nitrogen will open the valve 15, the nitrogen escaping thru this valve will carry away heat, so as to cool the remaining nitrogen, which in turn tends to extract heat from any argon with which it comes in contact. In the exemplified arrangement, a certain amount of gaseous argon will condense around the receptacle 10 and the lower part of the outlet 14, and a much larger amount will condense within the coil 24 and run down the conduit 26 to join the mass of liquid argon. Argon evaporating from the surface of the liquid mass tends to rise in the direction of the arrows and to move into the conduit 22 and thru the coil 24 to be condensed, until such time as the nitrogen has ceased to evaporate sufiiciently to open the valve 15, and a temperature equilibrium has been established between the argon and nitrogen.

It is, of course, not necessary that the receptacle be disposed within the cylinder which constitutes the container proper, and in certain instances it is advantageous that it be outside of the same, as when it is desired to render inoperative the action of the expendable gas. Fig. 2 illustrates such an arrangement. There is here provided a storage cylinder 5a which may be partially filled with liquid argon 6 and which is surrounded by insulation 30a. It has an outlet 20a leading to a safety valve 18a. The receptacle 10 for nitrogen is disposed, in the present instance, outside the cylinder 5a but within the insulation 3011, with portions of the conduit 220 which leads to coil 24 and of the conduit 26a which leads from coil 24 disposed, in the present instance, outside the cylinder a but within the insulation 30a. A valve 15 with an adjustable pressure control 16 is provided for the conduit 14 leading from the receptacle 10a. In the exemplified arrangement there is provided an outlet which has an openable valve 36 thru which liquid argon may be drawn off, a heater 37 which may be selectively operated as by an electric circuit 38 including a switch 40, and a valve 42 in the conduit 22a which may be closed to renderthe cooling effect of the evaporation of the nitrogen substantially ineffective on the body of argon in the container. Thus, when it is desired to draw off liquid argon from the container 5a, the valve 36 may be opened and the valve 42 closed, and the switch may be thrown to energize the heater 37. The heater will generate pressure within the container which will be insuflicient to open the safety valve 18a but which will be suificient to force liquid argon thru the conduit 35.

Since certain changes in carrying out the above process and in the constructions set forth, which embody the invention, may be made Without departing from its scope, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim:

1 The process of storing and shipping a valuable gas which comprises liquefying the gas, placing it in an insulated container, and providing in heat-transfer relationship therewith but out of communication therewith a liquefied expendable gas under conditions such that it will boil at a lower temperature than the'valuable gas,

and permitting escape of said expendable gas whenever the pressure thereof is increased by heat transfer from said valuable gas at a temperature of over substantially minus F., whereby evaporation of said other gas will reduce the temperature of said valuable gas to not over substantially minus 100 F., thus reducing the pressure in said container, wherein the control exercised by the expendable gas is rendered inefiective when the discharge of valuable gas from said container is desired,

2. Apparatus for storing and shipping a valuable gas comprising a container for the valuable gas, a receptacle for liquefied expendable gas, outlet means for said receptacle, means for normally maintaining said receptacle closed when in use and comprising a valve in said outlet means responsive to an increase in pressure Within said receptacle to open the same, a conduit leading from an upper point in said container and thru said receptacle and thence to a lower point in said container, said container, said receptacle, and said conduit being enclosed in an insulating covering, and said receptacle being mounted on the upper portion of one side of said container and being separated therefrom by insulation, and a control valve in said conduit;

References Cited in the file of this patent UNITED STATES PATENTS 1,680,873 Girardville Aug. 14, 1928 1,808,618 Trezise June 2, 1931 2,004,074 Kiley June 4, 1935 2,046,554 Gay July 7, 1936 2,059,942 Gibson Nov. 3, 1936 2,148,109 Dana et a1. Feb. 21, 1939 2,229,438 Birdsall Jan. 21, 1941 2,322,625 Geertz et al. June 22, 1943 2,682,154 Wilkinson June 29, 1954 FOREIGN PATENTS 685,425 Germany Nov. 23, 1939 w ll 

1. THE PROCESS OF STORING AND SHIPPING A VALUABLE GAS WHICH COMPRISES LIQUEFYING THE GAS, PLACING IT IN AN INSULATED CONTAINER, AND PROVIDING IN HEAT-TRANSFER RELATIONSHIP THEREWITH BUT OUT OF COMMUNICATION THEREWITH A LIQUEFIED EXPENDABLE GAS UNDER CONDITIONS SUCH THAT IT WILL BOIL AT A LOWER TEMPERATURE THAN THE VALUABLE GAS, AND PERMITTING ESCAPE OF SAID EXPENDABLE GAS WHENEVER THE PRESSURE THEREOF IS INCREASED BY HEAT TRANSFER FROM SAID VALUABLE GAS AT A TEMPERATURE OF OVER SUBSTANTIALLY MINUS 100*F., WHEREBY EVAPORATION OF SAID OTHER GAS WILL REDUCE THE TEMPERATURE OF SAID VALUABLE GAS TO NOT OVER SUBSTANTIALLY MINUS 100* F., THUS REDUCING THE PRESSURE IN SAID CONTAINER, WHEREIN THE CONTROL EXERCISED BY THE EXPENDABLE GAS IS RENDERED INEFFECTIVE WHEN THE DISCHARGE OF VALUABLE GAS FROM SAID CONTAINER IS DESIRED. 